Box the app creator (#1373)

egui_demo_app/src/lib.rs

@@ -19,5 +19,8 @@ pub fn start(canvas_id: &str) -> Result<(), wasm_bindgen::JsValue> {
     // Redirect tracing to console.log and friends:
     tracing_wasm::set_as_global_default();
 
-    eframe::start_web(canvas_id, |cc| Box::new(egui_demo_lib::WrapApp::new(cc)))
+    eframe::start_web(
+        canvas_id,
+        Box::new(|cc| Box::new(egui_demo_lib::WrapApp::new(cc))),
+    )
 }

egui_demo_app/src/main.rs

@@ -16,7 +16,9 @@ fn main() {
         drag_and_drop_support: true,
         ..Default::default()
     };
-    eframe::run_native("egui demo app", options, |cc| {
-        Box::new(egui_demo_lib::WrapApp::new(cc))
-    });
+    eframe::run_native(
+        "egui demo app",
+        options,
+        Box::new(|cc| Box::new(egui_demo_lib::WrapApp::new(cc))),
+    );
 }